John fielding



(No'Moael.) zsheets-sheet 1.

J. PIELDING. GAS ENGINE Patented Apr. 14,1891.

(No Model.) 2 Sheets-Sheet 2.

J. FIELDING. f

Q GASBNGINE.

\ LET s UNITED STATES PATENT OFFICE.

JOHN FIELDING, GLOUCESTER, ENGLAND.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No. 450,406, dated April14, 1891. i Application filed July 6, 1889. Serial No. 316,681. (Nomodel.)

To aZZ whom it may concern:

Be it known that I, JOHN FIELDING, of The- Atlas Works, in the city andcounty of Gloucester, England, have invented certain ing at full power,the charge being drawn in and compressed during one rotation and burnedand expelled during the next.

In carrying my invention into practice I employ two pistons working inseparate single acting cylinders, the working ends of which are in freeand constant communication with a common combustion-space. The pistonsare coupled by connecting-rods to two cranks on the same shaft in such amanner that the movement of one piston will be slightly in advance ofthe other.

For the purpose of admitting the charge and allowing the escape of thewaste products I employ miter-seated valves-viz., one each for theadmission of gas and air and a Vthird for the outlet of wasteproducts-which valves are in communication with the combustionspace andare worked by suitable levers operated by a single cam, which is rotatedby gearing once for every two revolutions of the crank-shaft.

The igniting apparatus may be of any suitable kind, such as used ingas-motor engines. The governor is attached to an oscillating arm and iscaused to act by centrifugal force should the normal speed ofoscillation of the arm be exceeded.

In the accompanying drawings, Figure 1 is a side elevation of agas-engine constructed according to my invention. Fig. 2 is a partialplan view. Fig. 3 is a cross-section on an enlarged scale. Fig. 4 is aside elevation, also enlarged and partly in section, of the valve boxand gear; and Fig. 5 is a sectional plan, on an enlarged scale, of aportion of the valvegear.

A is the main casting of the engine, carrying the bearings for thecrank-shaft B and two cylinders C C', placed side by side.

D is the valve-box placed at the end of the two cylinders, andwhichforms also an ignition or combustion chamber open to both cylinders C.C.

E E are pistons which are connected to the crank-shaft byconnecting-rods E2. The cranks are arranged so that one shall be aboutforty-five degrees in advance of the other.

In the drawings the piston E is shown with the crank on the dead-center,the piston E being in advance, in which position it will just be clearof the ignition-port F.

I have not shown in the drawings an igniting apparatus, as I may use anysuitable apparatus of the kind usually employed with gas-motor engines.

The valve-box D contains three mitervalves X Y Z. The valve X is thegas-valve, Y is the air-valve, and Z the exhaust-valve. (See Fig. 3.)

D' is avertical curved deiector or partition in the valve-box, theobject of which is to direct the entering air toward the gas, so as toobtain a better mixture than would be otherwise obtained.

The valves X Y Z are worked by a cam G, mounted on a stud-axle securedto the main frame A and driven at half-speed by gearing from thecrank-axle B. This cam G acts on a pivoted arm G', which is connected bya rod G2 with a crank-arm mounted on the outer end of a shaft H, carriedby a bracket extending downward from the valve-box D. On the inner endof this shaft H is mounted a toothed sector I, which gears with asimilar sector I,`mounted on a stud-axle set at right angles to theshaft H and secured to a bracket extending from the valve-box.

On the boss of the sector I are two lugs I2, against which the rods ofthe miter-valves Y. and Z rest. shaft H is rocked motion will becommunicated to the sector I and its lugs I2, and one or other (as thecase may be) of the valvesY Z will be raised, either to admit air or toexhaust. Adj usting-screws I3 are provided in the lugs to regulate theaction of the valves, and the valves are returned to their seats bysuitable springs.

The gas-valve X is actuated by a mechanism which I term a governor, andit consists of a curved arm or lever J, mounted on the shaft H, and tothe lower end of which is secured or pivoted a spring blade or arm J Itwill thus be seen that as the IOO blade J will miss the blade J 2, andthe requisite supply of gas will not be admitted to the combustionspace. l/Vhen the engine has slowed down to its normal speed, the bladeJ will then come again into position to act on the valve-rod X.

The action of the engine will be as follows: Let us assume that acombustible charge has been introduced and compressed readyforiignition, and the pistons are in the positionv shown in thedrawings-that is to say, the

piston E has uncovered the ignition-port F. The charge will then ignite,and the force of the explosion and the subsequent rapid expansion willdrive both pistons forward. On

the return-stroke the cylinders will be exhausted. On the next forwardstroke gas and air will be drawn in, and on the return-stroke will becompressed ready for ignition as soon as the piston E clears theignition-port F on its next forward motion. l/Vith' the two cylindersand the pistons connected with cranks in the manner described and shownthe maximum pressure of the ignited charge will act upon the leadingcrank (piston E) at the most favorable angle to exert a powerfulinfluence on the crank-shaft, while the expansion of the ignited chargetakes place at an extremely rapid rate, thus not only tending to reducethe loss of heat by radiation through the cylinder-walls, but alsoexerting a continuouslypowerful induence on the crank-shaft through thesecond or following crank, (piston E;`) also, by reason of thesimplicity of the valves and valve-gear an engine of extremelyeconomical construction is obtained.

Having now particularlydescribed and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim isl. In a gas-motor engine, the combination of twoworking-cylinders having a common combustion-space, two pistonsconnected to cranks on a crank-shaft and arranged so that 1.one crankrotates in advance of the other about one-eighth of a rotation, valvesfor the admission of gas and air, an exhaustvalve, a cani for workingall the valves through suitable gearing and driven at half the speed ofand from the crank-shaft, and a governor attached to an oscillating armand caused to act by centrifugal force, all substantially as hereinshown and described.

2. In a gas-motor engine, the combination of two working-cylindershaving a common combustion-space, two pistons connected to cranks on ashaft and arranged so that one crank rotates in advance of the otherabout one-eighth of a rotation, and valves suitably actuated for theadmission of gas and air and kfor exhaust purposes, respectively.

3. In a gas-motor engine, the combination, :with the gas-valve X,air-valve Y, and exhaust-valve Z, all arranged in one valve-box, of anoscillating shaft H, gearings I I', and rock-arm I2, transmitting themotion of the jshaft H to the valves Y Z, rockarm J, spring J., andweight J 2 for transmitting the motion of said vshaft to the valve X andthe cam G, driven by gearing from the crank-shaft of the engine, andconnect-ions, substantially such as described, for operating said shaftI-I from said cam, substantially as described.

4. In a gas-motor engine, the arrangement of governor as shown anddescribed,and consisting of an oscillating shaft suitably driven, acurved arm mounted on the shaft, and a weight carried by aspring-bladeattached to the curved arm, as set forth.

5. In a gasmotor engine, the combination, with two motor-cylinders andtheir pistons, the cylinders being placed side by side, of a valve-boxplaced opposite the ends of the cylinders and forming acombustion-chamber into which both cylinders open directly over theirwhole area, whereby the force of the explosion is applied simultaneouslyand with equal power to the pistons of the two cylinders, substantiallyas described.

In witness whereof I have hereunto set my hand thislth day of June,1889.

JOHN FIELDING.

Witnesses;

l-I. K. WHITE, A. W. SPACKMAN.

